Lateral File Drawer And Anti-Tip Device

ABSTRACT

An anti-tip device for a furniture piece having two drawers within a cabinet, and two keys that move with the drawers along a drawer axis. The keys have primary and secondary top surfaces with a valley therebetween, the valley defining a ledge wall. A lock bar is slidably secured to the cabinet and movable in a direction generally perpendicular to the drawer axis, and biased in a direction from the primary top surface to the bottom surface of each key. The lock bar has slots to receive the keys, and capture surfaces proximate to the slots on the side of the lock bar opposite the drawer. When one drawer is open the other drawer is moved toward the open position, the lock bar moves into the valley of the key so that the ledge wall abuts with the capture surface, thereby preventing further opening of the drawer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/167,277, filed Apr. 7, 2009.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to furniture, and in particular to a device that prevents two drawers of a furniture piece from being in the open position at the same time.

2. Description of Related Art

A problem that can arise during the use of furniture with drawers is that when two drawers are in the open position, the combined weight of the drawers, alone or in combination with their contents, shifts the center of gravity of the furniture. This shifting can cause the furniture to tip over.

SUMMARY OF THE INVENTION

The present invention is directed toward preventing two drawers in a piece of furniture from being opened at the same time. The anti-tip device for a piece of furniture has a first drawer and a second drawer within a cabinet. The device includes a first key attached to the first drawer and a second key attached to the second drawer, wherein each key moves with the respective drawer along a drawer axis. Each key has a bottom surface, as well as a primary top surface and a secondary top surface with a valley therebetween, the valley defining a ledge wall adjacent to the secondary top surface. The device further includes a lock bar slidably secured to the cabinet and movable in a direction generally perpendicular to the drawer axis, and biased in a direction from the primary top surface to the bottom surface of each key. The lock bar has a first slot and a second slot extending therethrough, the first slot being adapted to receive the first key, the second slot being adapted to receive the second key, wherein the interior of each slot has an engaging surface. The engaging surface is proximate to a capture surface on the side of the side of the lock bar opposite the drawer. In a first arrangement, each drawer is in a closed position and the keys extend through the slots of the lock bar, the engaging surface of each lock bar slot being supported by the primary top surface of each of the keys. In a second arrangement, one drawer is open so that the key no longer contacts the lock bar and the other drawer, from a closed position, is moved toward the open position such that the primary top surface moves past the slot and the bias causes the lock bar to move into the valley of the key so that the ledge wall of the key abuts with the capture surface of the lock bar, thereby preventing further opening of the drawer.

Still other desirable features of the invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description, taken with the accompanying drawings, wherein like reference numerals represent like elements throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear perspective view of a file cabinet having two drawers and an anti-tip device installed therein;

FIG. 2 a is an enlarged perspective view of the anti-tip device shown in FIG. 1 with portions of the lock housing not shown;

FIG. 2 b is a perspective view of the anti-tip device shown in FIG. 2 a, viewed along arrow A, with the file cabinet and drawers removed for clarity;

FIG. 2 c is an exploded perspective view of the anti-tip device shown in FIG. 2 b;

FIG. 3 a is a perspective view of the anti-tip device shown in FIG. 2 a, with the lock housing not shown, and with both file drawers in the closed position;

FIG. 3 b is a perspective view of the anti-tip device shown in FIG. 3 a, with one of the file drawers in the open position;

FIG. 3 c is a perspective view of the anti-tip device shown in FIG. 3 a, with one of the file drawers in the open position, and the other having been pulled toward the open position;

FIG. 4 a is a perspective view of a key in accordance with the present invention;

FIG. 4 b is a side view of the key shown in FIG. 4 a;

FIG. 5 a is a perspective view of a lock bar in accordance with the present invention;

FIG. 5 b is a side view of the lock bar shown in FIG. 5 a;

FIG. 6 a is a perspective view of a lock housing in accordance with the present invention;

FIG. 6 b is a side view of the lock housing shown in FIG. 6 a;

FIG. 7 is a perspective view of a first alternative embodiment of the key and lock bar shown in FIGS. 4 a and 5 a; and

FIG. 8 is a perspective view of a second alternative embodiment of the key and lock bar shown in FIGS. 4 a and 5 a.

DETAILED DESCRIPTION OF THE INVENTION

The present invention will now be described with reference to the accompanying figures. For purposes of the description hereinafter, the terms “upper”, “lower”, “right”, “left”, “vertical”, “horizontal”, “top”, “bottom” and derivatives thereof shall relate to the invention as it is oriented in the drawing figures. However, it is to be understood that the invention may assume various alternative variations and/or step sequences, except where expressly specified to the contrary. It is to be understood that the specific system illustrated in the attached figures and described in the following specification is simply an exemplary embodiment of the present invention. Hence, specific dimensions and other physical characteristics related to the embodiments disclosed herein are not to be considered as limiting.

FIG. 1 shows a file cabinet 2 having a first drawer 4 with a first side panel 5 and a second drawer 6 with a second side panel 7. The file cabinet 2 has a side wall 8 that extends vertically and substantially parallel to the first and second side panels 5, 7. The file cabinet 2 and drawers 4, 6 may be made of wood, metal, plastic, or any other suitably rigid material. The drawers 4, 6 may be opened by being pulled in direction X and closed by being pushed in direction Y. The directions X and Y define a drawer axis L1 and L2 for the respective drawers 4, 6. As shown in FIGS. 1 and 2 a, an anti-tip device 10 is installed substantially in a gap 11 created by the first and second side panels 5, 7 of the drawers 4, 6 with the side wall 8 of the file cabinet 2, at the rear end 4 a, 6 a of the drawers 4, 6. While the anti-tip device 10 is herein depicted and described as being installed into a file cabinet 2, it will be appreciated by those skilled in the art that the anti-tip device 10 may likewise be installed in various other types of furniture having drawers.

Referring to FIGS. 3 a-c, the anti-tip device 10 works generally as follows. Keys 12, 14 are provided on the side panels 5, 7 for each of the drawers 4, 6. The keys 12, 14 may be inserted into and removed from slots 36, 38 within a lock bar 32 which is biased in the downward direction by a spring 62. The lock bar 32 is slidably secured to the file cabinet 2, and is movable in a direction generally perpendicular to the drawer axis L1, L2. The keys 12, 14 include primary top surfaces 18 that allow the keys 12, 14 to maintain the lock bar 32 in an elevated position, resting on at least one of the keys 12, 14 while at least one of the drawers 4, 6 is fully closed. If one drawer is opened and the other is pulled toward the open position, the lock bar 32 will move off of the primary top surface 18 of the opening drawer and downward to engage with the surfaces of the unopened drawer's key to prevent the unopened drawer from being pulled open. The only difference between the arrangements illustrated in FIGS. 2 a-c and FIGS. 3 a-c is the presence of a lock housing 34 in FIGS. 2 a-c. The lock housing 34 is used primarily to support the lock bar 32 and as a result, FIGS. 3 a-c are provided for a clearer view of the operation of the moving parts, which otherwise are partially hidden by the lock housing 34.

As shown in FIGS. 3 a-c, the anti-tip device 10 includes a first key 12 and a second key 14. The keys 12, 14 are attached to the side panels 5, 7 of the drawers 4, 6, respectively, so as to be disposed between the side panels 5, 7 and the side wall 8. Holes 16 (see FIG. 4 a) are provided through the keys 12, 14 for attaching the keys 12, 14 to the side panels 5, 7 via screws, nails, or other fasteners, though the keys 12, 14 may be attached to the side panels 5, 7 by any other means known in the art such as with an adhesive. Directing attention to FIGS. 4 a and 4 b, each key 12, 14 is identical and the keys 12, 14 are substantially bar-shaped having an overall height H (FIG. 4 b) defined by the distance between a primary top surface 18 and a bottom surface 20 of the keys 12, 14. Toward one end of the keys 12, 14, the primary top surface 18 tapers forming a primary ramp 22, reducing the height of the keys 12, 14 to a portion having a locking height J, forming a lock surface 24. The height of the keys 12, 14, then abruptly increases to a portion having a ledge height K, where H>K>J, to form a ledge wall 26. Adjacent to the ledge wall 26 of each key 12, 14 is a secondary top surface 28 of height K, which again tapers, reducing the height of the keys 12, 14 and forming a secondary ramp 30. As shown in FIG. 4B, a valley 27 is formed on each key 12, 14 between the primary top surface 18 and the secondary top surface 28, wherein the valley 27 defines the surfaces of the ledge wall 26 and the primary ramp 22.

Referring again to FIGS. 2 a-c, the anti-tip device 10 also includes a lock bar 32 and a lock housing 34. As noted above, the lock bar 32 is generally disposed inside of the lock housing 34 and therefore is mostly hidden in FIGS. 2 a and 2 b. For illustration purposes, FIG. 2 a shows the lock housing 34 partially in phantom so that the operation of the lock bar 32 may be appreciated. FIGS. 3 a-c show the anti-tip device 10 including the lock bar 32, but with the lock housing 34 removed entirely to better depict how the present invention works, as will be further described below.

As shown in FIGS. 2 c and 3 a-c, the lock bar 32 is generally bar-shaped having a first slot 36 and a second slot 38. Referring now to FIGS. 5 a-b, the slots 36, 38 are defined by rectangular passages that extend through the lock bar 32 and define a first engaging surface 41 and a second engaging surface 43 on the interior perimeter of the slots 36, 38, respectively. As shown in FIGS. 3 b-c, and 5 a, proximate to the engaging surfaces 41, 43 on the side of the lock bar 32 opposite the drawers 4, 6, are a first capture surface 37 and a second capture surface 39, respectively. The slots 36, 38 may also have beveled edges 40 around the perimeters of the slots 36, 38 sloping inward toward the passages. At or near the center of the lock bar 32 is a hole 42, which will be described in more detail below.

As shown in FIGS. 6 a-b, the lock housing 34 has a substantially flat base portion 44 and a housing portion 46. Holes 48 are provided in the base portion 44 so that the lock housing 34 may be attached to the side wall 8 of the file cabinet 2 (as shown in FIG. 2 a) via screws, nails, or other fasteners, though the lock housing 34 may be attached to the side wall 8 of the file cabinet 2 by any other means known in the art, such as with an adhesive. As shown in FIG. 6 a, the housing portion 46 is substantially tube-shaped defining a conduit passageway 50 adapted to receive the lock bar 32 such that the lock bar 32 may slide freely through the conduit passageway 50 with little to no lateral movement inside the conduit passageway 50. See FIG. 2 a. Thus, the lock housing 34 permits movement of the lock bar 32 in the direction generally perpendicular to the drawer axis, while preventing movement of the lock bar 34 in the direction generally parallel to the drawer axis.

Returning to FIG. 6 a, the housing portion 46 also includes a first slot 52 and a second slot 54, defined by rectangular passages that extend through housing portion 46. The slots 52, 54 may also have beveled edges 56 around the perimeters of the slots 52, 54 sloping inward toward the passages. At or near the center of the housing portion 46 is an elongated hole 58 extending through the housing portion 46, which will be described in more detail below.

The slots 52, 54 of the housing portion 46 are sized and configured to have openings at least as large as the slots 36, 38 of the lock bar 32 to permit unencumbered motion of the keys 12, 14 therethrough (see FIG. 2 b). Although the slots 52, 54 of the housing portion 46 are shown as rectangular to correspond to the slots 36, 38 of the lock bar 32, the slots 52, 54 may be of almost any other shape or size as long as the slots 52, 54 are larger than the slots 36, 38 of the lock bar 32. With the lock bar 32 inserted into the conduit passageway 50 of the housing portion 46 as shown in FIGS. 2 a-b, the respective first slots 36, 52 and second slots 38, 54 are aligned to form passages through both the lock bar 32 and the housing portion 46. Further, the slots 36, 38 of the lock bar 32 and slots 52, 54 of the housing portion 46 are sized and configured to receive the respective keys 12, 14 as shown in FIGS. 2 a-b and 3 a-c.

As shown in FIGS. 2 a-c and 3 a-c, the anti-tip device 10 also includes a dowel 60 and a spring 62. The dowel 60 is inserted through the hole 42 of the lock bar 32 and attached to the lock bar 32. The dowel 60 extends laterally in both directions from the lock bar 32 through the elongated hole 58 of the housing portion 46 of the lock housing 34. As noted above, with the lock bar 32 inserted into the conduit passageway 50 of the housing portion 46 as shown in FIGS. 2 a-b, the respective slots 36, 38 of the lock bar 32 (FIG. 5 a) are aligned with the respective slots 52, 54 of the lock housing 34 so as to form passages through both the lock bar 32 and the housing portion 46 of the lock housing 34. When the slots 36, 38, 52, 54 are so aligned, the dowel 60 attached to the lock bar 32 is likewise aligned with and disposed within the elongated hole 58 of the lock housing 34.

The spring 62 is attached at one end to the dowel 60 and at the other end to the side wall 8 of the cabinet 2. Because the dowel 60 is contained by the elongated hole 58, the lock bar 32 can only move up and down through the conduit passageway 50 to the extent permitted by the elongated hole 58. The spring 62 provides a downward biasing force on the lock bar 32 through the dowel 60. It should be noted that although the spring 62 is depicted as being attached to the side wall 8 of the file cabinet 2, the spring 62 may also be attached to the lock housing 34, or to any other object that is stationary relative to the lock bar 32 so that the spring 62 still provides the downward biasing force. It should also be noted that gravity alone acting on the lock bar 32 provides a downward biasing force, but additional force provided by the spring 62 may be desired. Further, it will be appreciated by those skilled in the art that objects other than springs, such as elastic bands or weights, may be suitable to provide the downward biasing force on the lock bar 32.

To discuss the anti-tip device 10 in operation, reference will be made to FIGS. 3 a-c for ease of explanation, since FIGS. 3 a-c depict the anti-tip device 10 without the lock housing 34 shown. However, in view of the foregoing description, it should be understood that the lock housing 34 remains stationary with respect to the lock bar 32, keys 12, 14, and drawers 4, 6 during operation of the anti-tip device 10. Essentially, the lock housing 34 exists to retain the lock bar 32 in a position so that it may only move in the up and down direction as described below.

FIG. 3 a shows the anti-tip device 10 as installed into the file cabinet 2 with both the first and second drawers 4, 6 in the fully closed position. In this position, the engaging surfaces 41, 43 (FIGS. 5 a-b) of the slots 36, 38 of the lock bar 32 are engaged with the primary top surfaces 18 of the keys 12, 14, respectively. As shown in FIGS. 2 c and 3 a, the distance D between the engaging surfaces 41, 43 of the lock bar 32 is approximately equal to the vertical distance E between the primary top surfaces 18 of the keys 12, 14.

FIG. 3 b shows the anti-tip device 10 with the first drawer 4 moving toward the fully open position. Because the second engaging surface 43 of the second slot 38 (FIG. 5 b) is resting upon the primary top surface 18 of the second key 14, the lock bar 32 is vertically supported. The slots 36, 38 of the lock bar 32 are sized to have height H′ (FIG. 5 b), where H′≧H, such that the first key 12 having height H (FIG. 4 b) is afforded clearance to move uninterrupted through the first slot 36 when the lock bar 32 is resting on the primary top surface 18 of the second key 14. The first key 12 therefore is able to freely slide in and out of the first slot 36 because the first slot 36 remains so aligned with the first key 12 by virtue of the lock bar 32 being supported by the second key 14. Likewise, if the first drawer 4 is closed and the second drawer 6 were instead pulled open, the engaging surface 41 of the first slot 36 would be resting on the primary top surface 18 of the first key 12. This engagement would also vertically support the lock bar 32. In that case, the second key 14 would be able to freely move in and out of the second slot 38 because the second slot 38 would remain aligned with the second key 14 and provide clearance for the second key 14. In this manner, either the first drawer 4 or the second drawer 6 may be opened or closed without interference from the anti-tip device 10, as long as the other drawer remains in the closed position where the primary top surface 18 of the keys 12, 14 associated with that drawer supports the lock bar 32 in the elevated position.

FIG. 3 c shows what happens when the first drawer 4 is in the open position and the second drawer 6 subsequently is pulled toward the open position. Once the first drawer has been opened, the primary top surface 18 of the second key 14 is the only surface retaining the lock bar 32 in the elevated position. When the second drawer 6 is pulled toward the open position, since the first key 12 is removed entirely from the slot 36 of the lock bar 32, the vertical motion of the lock bar 32 is dictated entirely by the lateral motion of the second key 14. In particular, the engaging surface 43 of the second slot 38 of the lock bar 32 slides along the primary top surface 18 of the second key 14 until it reaches the primary ramp 22 (which is the same as the primary ramp 22 associated with the first key 12). As the engaging surface 43 of the second slot 38 follows the ramp 22, the lock bar 32 drops into the valley 27 of the key 14. The opening of the second drawer 6, combined with the downward biasing force the spring 62 exerts on the lock bar 32, forces the engaging surface 43 of the second slot 38 to slide down the primary ramp 22 and into the valley 27, to engage with the lock surface 24 (shown in FIGS. 3 b and 4 a-b). Any further opening of the second drawer 6 will cause the ledge wall 26 of the second key 14 to catch and abut the second capture surface 39 of the lock bar 32, preventing further movement of the second key 14 and attached second drawer 6 toward the open position because the ledge wall 26 cannot move past the capture surface 39 of the lock bar 32. Likewise, if the second drawer 6 were fully opened and a user attempted to pull the first drawer 4 open from the closed position, the lock bar 32 would drop into the valley 27 of the first key 12. The engaging surface 41 of the first slot 36 would engage with the lock surface 24 of the first key 12, such that any further opening of the first drawer would cause the ledge wall 26 of the first key 12 to catch and abut with the first capture surface 37 of the lock bar 32, thereby preventing the first key 12 from further movement toward the open position. Preferably, the spring 62 should be configured to provide downward biasing force sufficient to move the lock bar 32 into engagement with the lock surface 24 of a key 12, 14 even when the drawer is pulled toward the open position very quickly. The biasing force of the spring 62 maintains the lock bar 32 in engagement with the lock surface 24 of the second key 14 to prevent the second drawer 6 from opening.

To allow the second drawer 6 to then be opened, the first drawer 4 must first be closed. As the first key 12 moves back into the first slot 36, the secondary ramp 30 engages with the beveled edge 40 (FIGS. 5 a-b) of the lock bar 32 which is adjacent to the engaging surface 41. Further insertion of the first key 12 will cause the secondary ramp 30 to push the lock bar 32 upward against the downward biasing force provided by the spring 62. It should be noted that although the lock bar 32 is shown in FIGS. 5 a-b as having beveled edges 40 all around the perimeter of the slots 36, 38, each slot 36, 38 may include a beveled edge 40 only on the side of the slots 36, 38 adjacent to the engaging surfaces 41, 43, or may include no ramped edges at all, as long as the secondary ramp 30 and primary ramp 22 on the keys 12, 14 can effectively push upward on the lock bar 32 to lift the lock bar 32 as described herein. The beveled edges 40 may be included for convenience or ease of insertion of the keys 12, 14.

Once the secondary ramp 30 moves past the beveled edges 40 of the lock bar 32, the engaging surface 41 of the first slot 36 of the lock bar 32 will be engaged with the secondary top surface 28 of the first key 12. Further insertion of the key 12 will cause the lock bar 32 and engaging surface 41 to fall off the secondary top surface 28 and engage with the lock surface 24. Further insertion of the key 12 will finally cause the primary ramp 22 to push the lock bar 32 upward, against the downward biasing force provided by the spring 62, until the engaging surface 41 of the first slot 36 is engaged with the primary top surface 18 of the key 12. At this point, the engaging surface 43 of the second slot 38 has been lifted from the lock surface 24. Also, both slots 36, 38 of the lock bar 32 are once again aligned with the respective keys 12, 14 to allow uninterrupted passage of the keys 12, 14 through the slots 36, 38. Therefore, the ledge wall 26 of the second key 14 is no longer engaged with the lock bar 32 to prevent the second drawer 6 from opening.

In the event that a user of the anti-tip device 10 attempts to pull both drawers 4, 6 open at the same time, both drawers 4, 6 will be prevented from opening. As the keys 12, 14 slide out of the slots 36, 38, the opening of the drawers 4, 6 combined with the downward biasing force of the spring 62 will cause the engaging surfaces 41, 43 to slide down the primary ramps 22 and engage with the lock surfaces 24. At this point, any further opening of the drawers 4, 6 will be blocked by the engagement of the lock bar 32 with the ledges 26 of the keys 12, 14. In order to open either of the drawers 4, 6 at this point, one of them must be pushed closed, causing the primary ramp 22 of one of the keys 12, 14 to lift the lock bar 32 off of the lock surface of the opposite key and onto the primary top surface 18 to allow the opposite key to pass through the opposite slot, as described above.

During the initial assembly of the anti-tip system 10 into a file cabinet 2, both drawers 4, 6 will be in the opened position and will need to be inserted into the file cabinet 2. At this point, both keys 12, 14 will be outside the slots 36, 38 of the lock bar 32 and the dowel 60 will be pulled downward by the spring 62, causing the dowel 60 to engage with the lower edge of the elongated hole 58 in the lock housing 34. This engagement prevents the dowel 60 and lock bar 32 from being pulled any further downward by the spring 62. At this point, the lock bar 32 is in essentially the same position as shown in FIG. 3 c. One or both of the drawers 4,6 may then be pushed into the closed position. The primary ramp 22 and secondary ramp 30 on the keys 12, 14 will allow the keys 12, 14 to be inserted into the slots 36, 38 in the same manner described above for insertion of the first key 12 when the second drawer 6 has been locked.

If a user of the anti-tip device 10 needs to remove the drawers 4, 6 entirely from the file cabinet 2, the first drawer 4 may be removed without interference from the anti-tip device 10, provided that the second drawer 6 is in the closed position, as described above. However, to then remove the second drawer 6, the user would need to lift the lock bar 32 to allow the second key 14 to pass through the second slot 38. This can be accomplished by manually pulling upward on the dowel 60, which extends on the side of the lock bar 32 opposite of the spring 62. For this reason, the dowel 60 may be sized and configured to extend laterally from the lock bar 32 a distance sufficient to allow a user to grip it and lift the lock bar 32.

FIG. 7 shows an alternative embodiment of two keys 12′, 14′ and a lock bar 32′, which are similar to the keys 12, 14 and lock bar 32 shown in FIGS. 4 a and 5 a. In this embodiment, the keys 12′, 14′ have a symmetrical profile in that the various surfaces and ramps are mirrored on the top and bottom of the keys 12° , 14′. Similar to the keys 12, 14, the keys 12′, 14′ have a primary top surface 18′, a primary ramp 22′, a lock surface 24′ (shown in FIG. 7 to be rounded), a ledge wall 26′, a secondary top surface 28′, and a secondary ramp 30′.

The lock bar 32′ is essentially the same as lock bar 32, except that the first and second slots 36′, 38′ may be adapted to receive the somewhat different shape of the keys 12′, 14′ (e.g., by rounding the slots 36′, 38′ to better engage with the lock surface 24′), as is well understood in the art. As will likewise be appreciated by those skilled in the art, these various elements of the keys 12′, 14′ operate in essentially the same manner with respect to the lock bar 32′ as keys 12, 14 operate with respect to the lock bar 32. The primary and secondary ramps 22′, 30′ can push the lock bar 32′ in the upward position upon insertion through the slots 36′, 38′. Also, the lock surface 24′ and ledge wall 26′ can engage the lock bar 32′ within the slots 36′, 38′ to prevent the keys 12′, 14′ from moving out of the slots 36′, 38′.

FIG. 8 shows another alternative embodiment of two keys 12″, 14″ and a lock bar 32″, which are similar to the keys 12′, 14′ and lock bar 32′ shown in FIG. 7. The keys 12″, 14″ are similar to keys 12′, 14′, except that the keys 12″, 14″ are generally cylindrical with sloping conical sections at the ends of the keys 12″, 14″ that are inserted into the lock bar 32″. The keys 12″, 14″ contain analogous corresponding surfaces and ramps to the keys 12′, 14′ that function in essentially the same way. The keys 12″, 14″ have a primary top surface 18″, a primary ramp 22″, a lock surface 24″, a ledge wall 26″, a secondary top surface 28″, and a secondary ramp 30″. As will be appreciated by those skilled in the art, these various elements of the keys 12″, 14″ operate in essentially the same manner with respect to the lock bar 32″ as keys 12, 14 operate with respect to the lock bar 32. The lock bar 32″ is essentially the same as lock bar 32′, except that the first and second slots 36″, 38″ may be further adapted to receive the somewhat more rounded shape of the keys 12″, 14″, as is well understood in the art.

Further, while the anti-tip device 10 is shown and described herein as being used for vertically oriented drawers, the anti-tip device 10 may also be adapted to be installed into a piece of furniture having drawers that are horizontally oriented side by side. As an example, if the arrangement illustrated in FIG. 1 were turned on its side and the lock bar 32 were biased by a spring or other biasing member, the device would operate in essentially the same manner described above, but in a horizontal orientation. As will be appreciated by those skilled in the art, such adaptation would include modifying the placement and orientation of the keys and lock bar, as well as configuring the spring or other biasing member to force the lock bar in a horizontal instead of a vertical direction.

The invention has been described with reference to exemplary embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. 

1. An anti-tip device for a piece of furniture having a first drawer and a second drawer within a cabinet, comprising: a first key attached to the first drawer and a second key attached to the second drawer, wherein each key moves with the respective drawer along a drawer axis, each key having a bottom surface, each key having a primary top surface and a secondary top surface with a valley therebetween, the valley defining a ledge wall adjacent to the secondary top surface; and a lock bar slidably secured to the cabinet and movable in a direction generally perpendicular to the drawer axis and biased in a direction from the primary top surface to the bottom surface of each key, the lock bar having a first slot and a second slot extending therethrough, the first slot being adapted to receive the first key, the second slot being adapted to receive the second key, wherein the interior of each slot has an engaging surface, the engaging surface being proximate to a capture surface on the side of the side of the lock bar opposite the drawer; wherein, in a first arrangement, each drawer is in a closed position and the keys extend through the slots of the lock bar, the engaging surface of each lock bar slot being supported by the primary top surface of each of the keys; and wherein, in a second arrangement, one drawer is open so that the key no longer contacts the lock bar and the other drawer, from a closed position, is moved toward the open position such that the primary top surface moves past the slot and the bias causes the lock bar to move into the valley of the key so that the ledge wall of the key abuts with the capture surface of the lock bar, thereby preventing further opening of the drawer.
 2. The anti-tip device of claim 1, wherein the ledge wall extends into a lock surface at the bottom of the valley, wherein in the second arrangement of the anti-tip device, the engaging surface of the slot associated with the unopened drawer abuts with the lock surface of the key associated with the unopened drawer.
 3. The anti-tip device of claim 2, wherein the keys each have an overall height at the primary top surface, a locking height at the lock surface, and a ledge height at the secondary top surface, the overall height being greater than or equal to the ledge height, and the ledge height being greater than the locking height.
 4. The anti-tip device of claim 1, the keys each further comprising a primary ramp extending from the primary top surface into the valley, such that when the anti-tip device is in the second arrangement and the key associated with the unopened drawer is inserted further into the associated slot, the lock bar is displaced by the primary ramp in the direction opposite of the bias, thereby permitting the key to be inserted into the slot so that the anti-tip device is in the first arrangement.
 5. The anti-tip device of claim 4, wherein when the lock bar is being displaced by the primary ramp of a key, the engaging surface of the slot abuts with the primary ramp.
 6. The anti-tip device of claim 1, wherein the keys each further comprise a secondary ramp adjacent to the secondary top surface and opposite the ledge wall, such that when the anti-tip device is in the second arrangement and the open drawer is pushed toward the closed position, the secondary ramp engages the engaging surface of the slot and displaces the lock bar in the direction opposite of the bias, thereby permitting the key of the open drawer to be inserted through the associated slot.
 7. The anti-tip device of claim 4, wherein the keys each further comprise a secondary ramp adjacent to the secondary top surface and opposite the ledge wall, such that when the anti-tip device is in the second arrangement and the open drawer is pushed toward the closed position, the secondary ramp displaces the lock bar in the direction opposite of the bias, thereby permitting the key of the open drawer to be inserted through the associated slot.
 8. The anti-tip device of claim 1, further comprising a lock housing attached to the cabinet and having a conduit, the lock bar being received within the conduit, the lock housing permitting movement of the lock bar in the direction generally perpendicular to the drawer axis while preventing movement of the lock bar in a direction generally parallel to the drawer axis.
 9. The anti-tip device of claim 8, wherein the lock bar further comprises a laterally extending dowel and the lock housing further comprises an elongated hole through which the laterally extending dowel extends, the elongated hole defining the limits of displacement of the lock bar in the direction of and opposite of the bias.
 10. The anti-tip device of claim 9, wherein the bias is provided by a spring attached at one end to the lock bar and at the other end to the cabinet.
 11. The anti-tip device of claim 1, wherein the bias is provided by gravity. 